ZigBee Based Wireless Sensor Networks and Its Applications in Industrial Shizhuang Lin, Jingyu Liu a

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ZigBee Based Wireless Sensor Networksand Its
Applications in Industrial Shizhuang Lin, Jingyu
Liu and Yanjun FangDepartment of
AutomationWuhan University(IEEE International
Conference on Automation and Logistics, Aug.
2007)
Date Oct. 31 2007 Sung-joo Lee forstar_at_postech
.ac.kr DPNM Lab., GSIT, POSTECH
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Outline

• Introduction - What is ZigBee?
• ZigBee Technology
• WSN Based on ZigBee
• Nodes Design
• Industrial Applications
• Conclusions

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What is ZigBee?

• Technological Standard Created for Control and
  Sensor Networks
• Based on the IEEE 802.15.4 Standard
• Created by the ZigBee Alliance
• Named for erratic, zig-zagging patterns of bees
  between flowers
• Symbolizes communication between nodes in a mesh
  network

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IEEE 802.15.4 ZigBee In Context
Application
Customer

• the software
• Network, Security Application layers
• Brand management
• IEEE 802.15.4
• the hardware
• Physical Media Access Control layers

API
Security 32- / 64- / 128-bit encryption
ZigBee Alliance
Network Star / Mesh / Cluster-Tree
MAC
IEEE 802.15.4
PHY 868MHz / 915MHz / 2.4GHz
For ZigBee alliances of companies worked to
develop specs so that the commercial potential
of the standards could be realized
Stack
Silicon
App
Source http//www.zigbee.org/resources/documents/
IWAS_presentation_Mar04_Designing_with_802154_and_
zigbee.ppt
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The Wireless Landscapes
The quick, short text transmission!
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ZigBee and Other Wireless Technologies
Source http//www.zigbee.org/en/about/faq.asp
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ZigBee Aims

• Low data rate
• Low power consumption
• Small packet devices

ZigBee should be widely used in

• Building automation
• Personal healthcare
• Consumer electronics
• PC its peripherals
• Industrial control
• Residential/light
• Commercial control

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ZigBee Frequencies

• Operates in Unlicensed Bands
• ISM 2.4 GHz Global Band at 250kbps
• 868 MHz European Band at 20kbps
• 915 MHz North American Band at 40kbps

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Wireless Sensor Network(WSN)

• The random distributed small nodes with sensors,
  the data processing unit and the connection
  module constitute network through a
  self-organizing way
• By the sensors detecting with hot, infrared,
  sonar, and radar, nodes survey and send the data
  to the sink nodes using the multi-hop
  communication.
• Finally, data of the entire area are transferred
  to the long-distance centers.

• Some limitations are exposed
• Sensor nodes number, ability of communication,
  Power supply and ability of data processing
• So, ZigBee was improved to solve these problems

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ZigBee s Topology

• Topology
• Star
• Cluster Tree
• Mesh
• Network coordinator, routers, end devices
• States of operation
• Active
• Sleep
• Nodes
• Full Function Nodes (FFN)
• Reduced Function Nodes (RFN)
• Modes of operation
• Beacon
• Non-beacon

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ZigBee s Topology(Contd.)

• Characteristics of Star Network
• - One central routing and control point
• - Single-hop-point to multi-hop point
• - All data flows through central point

• Characteristics of Mesh Network
• - Multiple data path
• - Multi-hop
• - Self configuring and self healing

• ZigBee supports both star topology and mesh
  topology
• In the mesh topology, the FFN in the network may
  communicate without the aid of the network
  coordinator
• Based on the flexible topology, ZigBee network
  overcomes barriers to wireless adoption of
  reliability and using simplification
• By virtue of multi-hop capability, ZigBee can
  cover very wide area (e.g. industry, building)

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New WSN System with ZigBee nodes (NWSNS)

• Based on the ZigBee flexibility and reliability
  to consummate the WSN system, they proposed a new
  ZigBee nodes based WSN system (NWSNS) structure.

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New WSN System with ZigBee nodes(NWSNS)

• The physical layer, data link layer, and the
  network layer wholly take over the definitions of
  the corresponding layers in ZigBee

• The transport layer and the application layer
  partly adopt the functional definitions of the
  corresponding layers in ZigBee

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Physical layer of NWSNS

• Three radio bands are defined
• - Global use ISM 2.4 GHz Global Band at
  250kbps
• - USA and Australia 915 MHz North American
  Band at 40kbps
• - Europe 868 MHz European Band at 20kbps

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Data link layer of NWSNS

• The data link layer is controlling access to the
  shared radio channel.
• It generates and recognizes the addresses,
  verifies the frame check sequences.

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Network layer of NWSNS

• The network layer is managing the network
  structure and handles routing and security
  functions for the relayed messages.
• The WSN network is a dynamic network and the
  network layer needs to maintain the information
  about the nodes within the network.

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Transport layer of NWSNS

• This layer is needed when the system is planned
  to be accessed through Internet or other external
  networks
• It should be partly adopt the functional
  definitions of ZigBee, such as whether the device
  is FFN or RFN, network security functions and the
  responds and actions to the system events

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Application layer of NWSNS

• The application layer remained all th edefinition
  of the traditional WSN system
• Three possible application layer protocols
• - Sensor management protocol (SMP)
• - Task assignment and data advertisement
  protocol (TADAP)
• - Sensor query and data dissemination protocol
  (SQDDP)

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Node Design - H/W

• Traditional WSN node design

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Node Design - H/W (contd.)

• Structure of the new WSN nodes
• Data transfer unit, process unit, data
  acquisition unit and power unit parts are remained

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Node Design - H/W (contd.)

• Structure of the new WSN nodes
• The data transfer unit
• - The ZigBee module is embedded to match the
  MAC layer and the NET
• layer of the ZigBee protocol
• - The ZigBee unit should be dynamically
  configured and switched into the resting module
  to save the power

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Node Design - H/W (contd.)

• Structure of the new WSN nodes
• Some integrated solutions for the ZigBee transfer
  unit
• - Many ZigBee protocol chips which integrated
  the CPU, RF transceiver, net protocol and the RAM
• - Based on the chips, many module for the
  ZigBee protocol is provided and the ZigBee
  transfer unit could be easily designed based on
  the modules

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Node Design - H/W (contd.)

• Structure of the new WSN nodes
• The data acquisition unit
• - An optional controller is designed to build
  up a closed loop for the different tasks
• - Based on the new WSN nodes design, a close
  loop WSN network with control function is realized

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Node Design - S/W

• The software design includes the communication
  software and the application software
• The communication software
• Defined by the ZigBee transfer unit in a large
  scale
• To be a steady system
• The application software that materializes the
  WSNs functions is the most important part
• In the software design of the nodes, TinyOS is a
  good tool

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TinyOS

• An open-source operating system designed for
  wireless embedded sensor networks
• A component-based architecture which enables
  rapid innovation and implementation while
  minimizing code size as required by the severe
  memory constraints inherent in sensor network

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TinyOS (contd.)

• Based on the TonyOS, a full configurarion of the
  nodes of NWSNS is composed by a scheduler and a
  series of components
• The TinyOS have provided the universal components
  (such as main components) and some data
  communication and acquisition components, which
  separate the users and the hardware ground
• The users just need to program the components of
  the user application layer

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TinyOS (contd.)

• Two types of components in an application
• Modules
• Configurations
• Modules provide application code, implementing
  one or more interface
• Configurations are used to assemble other
  components together, connecting interfaces used
  by components to interfaces provided by others
  -gt Wiring
• Every application is described by a top-level
  configuration that wires together the components
  inside

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Industrial Applications

• For its reliability and flexibility, the NWSNS
  has much more vast range of prospect than the
  traditional WSN system
• In an industrial application, there are some
  characteristics desired for a wireless data
  networks
• Range At least 50m range is required in
  industrial RF environment. ZigBee is designed
  10100m range
• Data rate In industrial sensing and control
  applications required data rates vary widely by
  application but are often low and intermittent.
  The NWSNS should be improved for ZigBees
  shortage on high rate transmission

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Industrial Applications (contd.)

• Network latency It should be possible to tune
  the network availability or response to the
  application requirement at the end-node to
  optimize performance. ZigBee nodes need to wake
  up very quickly, transmit and/or receive and go
  back to sleep
• Power profile ZigBee has been developed
  specifically to permit low power consumption and
  years of battery life
• Security ZigBee has security built in 802.15.4
  specifies use of the 128-bit advanced encryption
  standard
• Operating Frequency Operated in one of the
  unlicenced bands for operating cost and
  regulatory reasons. ZigBee supports most of the
  widely used unlicensedISM bands around the world

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Industrial Applications (contd.)

• Networktopology Multiple-hops make network
  traffic more complex but will increase the
  network resilience and reliability
• Number of devices In most real industrial area,
  hundreds and thousand of devices could be
  required. ZigBee have a great capability to
  address the spectrum of industrial situations
• Flexibility Attached and implemented for
  different device types without a lot of
  device-specific requirements. ZigBee is flexible
  and can carry and type of data
• Resilience and reliability During the network
  implementation it should be possile to design out
  unnecessary single points of failure. ZigBee is
  perfect due to data packet Ack, CSMA-CA,
  encryption, mesh multi-path transmission

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Conclusion

• ZigBee technology is a new wireless protocol that
  widely used various areas for its performance in
  reliability, power profile, capability,
  flexibility and cost. So it is significant to
  embed the ZigBee into WSN system that widely
  applied now
• In this paper, they proposed a new node designed
  that integrate the WSN nodes and ZigBee module
  together
• The realization and application of the NWSNS in
  industrial need much more experiment and test.
  But all of the characteristic have shown that the
  NWSNS will have a vast range of prospects

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Questions?

• Thank you!